As far as the applicant is concerned, door locks which need to be used together with keys are usually used in access doors or bathroom doors in the existing technologies. However, these door locks usually have the following shortcomings: (1) many parts, non-modular structure and cumbersome assembly, thus being inconducive to the enhancement of production efficiency; (2) inadequate fastness and the shell is prone to deformation or even fracture under big impact, thus leading to functional failure of locks.
Chinese utility model patent (Patent No. 01264119.7) has disclosed the specific structure of a latch used in a door lock. Although with less parts, its locating structure for parts are mainly located on the shell, so, on the one hand, it makes assembly quite difficult. On the other hand, in case of deformation of the shell under outside force, the internal parts are prone to shifting, causing latch failure.